Gas flow regulators are used to provide a medical gas, such as oxygen, to a patient from a source supply of the gas. The gas is normally stored in a cylinder or supply vessel under high pressure. The gas flow regulator reduces the high pressure (about 500-3000 psi) to a lower pressure (about 50 p.s.i.) and provides the gas at a metered flow rate, usually measured in liters/minute. It is desirable to manufacture gas flow regulators as a compact, light weight and smooth to the touch package. It is also desirable to color code the devices to indicate the gas being handled (e.g., green for oxygen) or the preference of the owner of the device. Furthermore, the use of bar coding can facilitate accurate tracking and identification of the devices.
One solution to the prior art problem is to manufacture regulators having an aluminum alloy housing. Aluminum can be milled into a suitable shape for use as a regulator. The aluminum can also be color anodized and etched. Unfortunately, the use of aluminum in the flow path of oxygen is believed to be a potential fire hazard, because aluminum can be ignited when exposed to a pure oxygen environment.
Unlike aluminum, brass is resistant to ignition. It is therefore desirable to manufacture compact gas flow regulators from a brass material.
While a brass regulator can also be compact, lightweight and smooth to the touch, the use of brass as a construction material does provide some disadvantages. Etching of the bar code onto a brass regulator, although permanent, is not a viable option because typical bar code scanners cannot read etched brass. Another disadvantage involves color coding. Brass regulators can typically be plated only with nickel, which limits the coloring of the brass regulators to a metallic color. Typical bar code readers also cannot read etched nickel.
Although adhesive labels made from a thin paper or plastic material can be used for the color coding and bar coding, they can be removed or can wear off the regulator.
In accordance with embodiments of the invention, an essentially permanent label can be attached to the body of a flow regulator. The label can be as durable as the regulator body. The label can also be attached in such a way as to inhibit removal of the label without physical damage to the regulator or label.
In a particular embodiment, a regulator attaches to a fluid source, such as a gas supply source, and control includes elements that the flow of fluid from the fluid source. The regulator includes housing that can be formed of a first material. The regulator can also include a label formed of a second material, where the label is non-removably mounted to the housing.
The label can be formed of a continuous walled structure, such as a cylinder. The label for a regulator can include an inner surface for mounting to the regulator. The label and housing can also include an attachment mechanism for securing the label to the housing. The attachment mechanism can include a pressure fit or an adhesive such as epoxy, for example.
The label can further include a permanently etchable surface for inclusion of an etched design, such as a bar code. The label can also include a permanently colorable surface for inclusion of a color layer. The color layer can be formed of an anodized material. Specifically, the second material of the label can be an aluminum alloy.
The label can also include an orifice that, when the label is attached, coaxially aligns with a relief vent on the housing. The relief vent is particularly fabricated to eject over-pressured fluid from the relief vent, which may result from a flame-out. The orifice is dimensional to decrease the likelihood that the label would be contacted, and possibly ignited, by a flame or hot gas ejected from the relief vent. This is especially important when the label is fabricated from an ignitable material, such as aluminum.